Thread-wound golf balls having a balata cover are well known in the art. They are generally manufactured by winding a length of thread of high quality natural rubber or synthetic rubber on a solid center of high repulsion synthetic rubber or a liquid center. The resulting thread-wound core is enclosed in a balata cover. The assembly is shaped in a mold through the application of heat and pressure to form dimples in the cover surface. Then the cover is vulcanized by an immersion or gas vulcanization methods. The immersion vulcanization method is to immerse the ball in a solution of a vulcanization accelerator. The gas vulcanization method is to maintain the ball in an atmosphere of a vulcanizing agent gas.
Many skilled players and professional golfers favor these thread-wound golf balls having a balata cover because they offer a pleasant feel upon hitting, improved directional control and spin properties so that they can be controlledly hooked or sliced.
The thread-wound golf balls having a balata cover, however, suffer from the problem that the cover is less resistant to cut and shearing (chipping and peeling) and thus less durable. It is thus desired to improve their durability, especially the cut and shear resistance of the cover.